Attachment: Hassan Rouhani, Ali Akbar Salehi, Mohammad Nahavandian
Iranian President Hassan Rouhani, center, accompanied by the head of Iran’s Atomic Energy Organization Ali Akbar Salehi, right, and his chief of staff Mohammad Nahavandian, listens to Iran’s national anthem while attending a ceremony marking National Nuclear Technology Day, in Tehran, Iran, Thursday, April 9, 2015. Rouhani warned that Tehran will not sign on to a final nuclear deal with world powers unless it is predicated on the lifting of economic sanctions imposed on Iran over the controversial nuclear program. (AP Photo/Vahid Salemi)